Crankshaft bearing polishing machine



Jan. 20, 1942. F. W. HAEGER ETAL CRANKSHAFT BEARING POLISHING MACHINE Filed Jan; 27, 1940 4 Sheets-Sheet l 5 z @www5 I@ um? Izzi Gtfornegs F. W. HAEGER ET AL CRANKSHAFT BEARING POLISHING MACHINE Jan. 20, 1942.

4 Sheets-Sheet 2 Snventors Filed Jan. 27, 1940 Jan. 20, 1942. F. w. HAEGER ErAL CRANKSHAFT BEARING POLISHING- MACHINE Filed Jan. 27, 1940 4 Sheets-Sheet 3 H II Snoentors Jan. 20, 1942. F W HAEGER ETAL 2,270,522

CRANKSHAFT BEARING POLISHING MACHINE :Snnentors WL' v Gttornegs v Patented Jan. 20, 1942 CRANKSHAFT BEARING POLISHIN G MACHINE Frank W. Haeger and Emil P. Rohrbach, Lansing, Mich., assignorsto General Motors Corporation, Detroit, Mich., a. corporation f Dela- Wavre Application January 27, 1940, Serial No. 315,908

3 Claims. ,.(Cl. 5l-154) This invention relates to machines for polishing the main journals and crankpins of the crankshafts used on internal combustion engines ofV automotive vehicles.

The essential novelty of the machineV resides f in the provision of a table adapted to slide to and from the crankshaft to be polished. The table is provided with two master crankshafts, duplicates of the crankshaft to be polished. The crankshafts have secured thereto a plurality of arms, the ends of which are provided with polished heads which engage the bearings of the shaft when the table is moved toward the crankshaft. The machine is power operated in vsuch a way that the two master cranks and the crankshaft to be polished rotate in unison, and the rotation of the cranks and the shaft, together with the movement of the table toward the crankshaft, causes the emery paper or other abrasive material to polish the bearingsv of the Shaft.

Cams are used to slide the table toward the crankshaft and each cam is so formed that for the initial part of their rotation the cams tightly] press and hold the abrasive material against ables a flushing oil to be flowed therebetween to remove any free abrasive, or grit of any kind. The cam then again moves the table toward the crankshaft and causes the abrasive material to be pressed tightly against the bearings and the subsequent peripheral shape of the cam is such that there is a very gradual release of the pressure of the polishing heads against the bearings until the pressure is entirely released. The crankshaft is then removed and another crankshaft placed in the machine.

The speciiic polishing head also forms a novel part of the invention, this polishing head being spring pressed against the bearings on the crankshaft for the rst part of the polishing' movement. Continued movement of the'table toward the crankshaft causes the spring of the head to be shut tight and the pressure thereafter against the bearings is contant.

A further object of the invention is the provision of an oscillatable carriage on which the crankshaft to be polished is mounted. The width of the polishing heads isslightly less than the width of the bearings, and in order to enable the entire bearing surface to be polished the carriage is given a reciprocating motion through a very short arc. This reciprocatingmotion enables the abrasive on the polishing head to polish the entire bearing.

On thedrawings,

Figure 1 is a plan view of the polishing machine With parts broken away'` and shown in section.

Figure 2 is an end elevation of the machine with parts broken away and shown insection better to illustrate the construction.

Figures 3, 4, and 9 are sections on the corresponding lines of Figure 1.

Figure 5 is an enlarged detailed view of the polishing head.

Figure 6 is a detailed view on the line 6-6 of Figure 4.

Figure 7 is a sectional detailedv View on the line I-'I of Figure 8.

Figure 8 is a sectional detailed view on the line 8-8 of Figures 1 and 7.

Figure 10 is a sectional detailed view on the line IU-IO' of Figure 2.

Referring to the drawings, the machine as a whole is indicatedat 2. The machine is provided with the upright frame 4 (Figure 4) at the upperpart of which there is the flat table-like part 6. On the tablev 6 at one side of the machine there is secured the subframe 8 having the upstanding ends I8 provided with openings in each of which a bearing I2 is mounted. In the bearings I2 the shaft I4 is mounted. The shaft I4 has a worm wheel I6 secured to one end thereof, and a worm I8 is mounted in the housing 2|] and meshes with the' worm wheel I6. The worm I8 is secured to a shaft 22 which is connected to an electric motor 24 by means ofsuitable gearing provided in a housing, 26.

The shaft I4 has two similar cams 28 and 38 secured thereto and positioned immediately adjacent the inner edgev of. the uprights I0 of the subframe 8. Immediately adjacent.l the subframe 8 there is mounted the sliding or reciprocable table` indicated as a whole at 32. This tablehas the end column-like bearing parts 34 and 35v which surround the bars or rods 38 and 40 and are adapted to slide thereon. The table comprisesthe upwardly projecting stationary polishing arms-42, 44, 46, and 48 and each of these arms is provided with bearings having the removable bearing caps 58 and. 52. The bearings are for the purpose of receiving the main bearings 54 of two master crankshafts 55 and 58. These master crankshafts 5S and 58 are in all respects substantial' duplicates of the crankshaft 60 which has the bearings which are to be polished.

The throws 62 of the master crankshafts have mounted on the bearings thereof the rotatable polishing arms 64, and these arms 64 are adapted to rotate with the crank throws of the master crankshafts 56 and '58.

Referring to Figure 1, the right hand ends of the master crankshafts 56 and 58 are enclosed in a box 66 and in this box there are enclosed the gears 68, 10, and 12. Gears 68 and 12 are secured to the ends of the master crankshaft 56 and 58 respectively, while the gear 10 is an idler.

the cranks 56 and 58 may be movedin unison.

The ends of the arms 42, V44, or 46 and 48 as well as the ends of the rotatable arms 64 are provided with polishing devices indicated as a whole at 14. One of these polishing devicesis indicated in detail in Figure 5. The end of each ,arm-42, 44, 46, `48 and 64 is'provided with a bore .16 -in which the bearings 18` are'positioned. In these bearings 18 there is received the shank 80 integral with the polishing head 82. The device 14 has an additional bore 84 inwhich there is received a guiding pin 86 rigidwith the head 82.

The head 82 hasI a central recess 88 and the arcuate polishing surfaces 90 and 92. The polishing surfaces90 and 92 are given a shape corresponding to the shape of the bearing part 94 on the crankshaft 60 and between the bearing parts 90 and 92 and the bearing part 94 of the crank shaft an abrasive such as a strip of emery paper 96 is positioned. The; surfaces 90 and 92 preferably have a strip of emery cloth cemented thereto, the emery paper 96 being between the emery cloth and the bearing.

At the bottom of the recess 88 the pin or shaft 98 is mounted on T-shaped brackets |00 secured to the two'sides of the head 82. The emery paper is passed underneath the pin 98 and retains that part of the emery paper not in contact with the polishing faces 92 and 90 away from the bearing part 94.

The polishing device 14 formed in each of the polishing arms and in this recess the coil spring |04 is positioned. The end of the shank 80 is threaded` and has a nut |06 secured thereto. Y A washer |08 is positioned between the nut |06 and the end face of the recess |02. The nut |06 and washer |08 limit the movement which the spring |04 may give to the shank 80. y

The end of the shank is reduced as indicated includes a recess |02 at ||0 and fits into the cylindrical socket ||2 :g55

which is received in the spring |04. The socket is provided with an end flange ||4 and fits over they end of the coil spring |04.

4The description ofthe structure of Figure 5 for one of the polishing devices will suice for all of them. The single difference will be in the width of the device or the shape of the polishing surface 90 or 92, but they are structurally otherwise identical.

The ends of the arms 42 and 44 and the ends of the arms 46 and 48 are united by means of the rods ||6 and ||8 to make the structure more rigid and to serve as a mounting for the rollers |26. The arms 42, 44, 46 and 48 are secured to the table 32 in the manner shown in Figure 6. The arms have the lateral flanges |20 and these flanges are provided with a plurality of openings through which there pass the machine screws at |22 which are threaded into the sliding table 32.` Y Y Each of the arms 42, 44, 46 and 48 is provided with a bore |24 therethrough and through this bore there is led the strip of emery cloth 96 used to polish the crankshaft bearings.

For the rotatable arms 64 the emery cloth 96 merely passes freely over the top of the sliding table 32 as is best shown'in Figures 4 and 6.

The cams 28 and 30 operate against rollers |26 which are secured to the ends of the bars ||6 and ||8 and the rotation of the cams 28 and 30 moves the table 32 toward the crankshaft 60. The reverse movement of the table is caused by means of the lever |28 and the weight |30. The

weight is pivoted to the end of the lever at |32 and the lever in turn is pivoted at |34 to an arm |35 attached to the frame 4 of the machine. The free end of the lever |28l is provided with a roller |36 which bears against one side of the table 32. This structure is best shown in Figure 4.

In order that the master crakshafts 56 and 58 may berotated, theshaft 56 is joined by means of-anadjustable connection |38 to a shaft |40 whichhasv secured thereto the gear |42 which meshes with the gear |44A rigidly mounted on a collar |46 which in turn is rigidly mounted in the housing-|48. As indicated at |50, the collar |46 issplined on a power shaft |52 driven from an electric motor |54. When the cams 28 and 30 move the slidable table 32, the collar |46 will slide on the splines |50 of the shaft.

The crank shaft which has the bearings to be polished-is mounted on an oscillatable carriage indicated as a whole at |56. This carriage has two downwardly` extending studs or trunnionsjournaled in the sockets |58 which inturn have the integral sockets |60 which are mounted on pins |62 supported in bearing eyes |64 formed on a frame |68 secured to the base 4 of the ma- .chine by means of the machine screws |10.

. The table |56 has openings |12 formed therein in alignment with the main bearings of the crankshaft 60. In each of these openings there is receiveda shank |14 which has thereon a head |16 on which there are pivotally mounted the rollers Q |18.' This head |16 is stationary and serves as a backing for the main bearings 94 of the crankshaft 60.

The Areciprocating carriage is provided with a tail stockV |best shown in Figure 3. This tail stock is mounted in an upright |82 formed on the oscillating'carriage |56. A cylinder |84 is secured by means of the flange |88 and the machine screws |86 to the side of the upright |82. IIn this cylinder there is the piston |90, and theend of the cylinder is closedby the head |92. The, piston has secured thereto the rod |94 which passes through the head |92. The rod has secured thereto the piston |96 which is air operated from the cylinder |98 and the admission of air to the cylinder |98 by means of suitable piping will move the piston to the left.

',A,set screw 200 secured in the cylinder |84 has its end tting in a slot or groove 202 in the piston' and guides the piston |90 in its movement.

.Ther piston |90 is hollow and has'. rotatably mounted therein the holder 204, the end of which is hollow and is adapted to receive -theend 206 of the crankshaft 60. Roller bearings208 and 2|0 rotatably mount Ithe shaft 2|2 of the .holder 204 in the. piston |90 and the end `cap 2|4v holds the bearing and holder-in. the piston |90. A lubricant' seal 2|5 is' provided between the shaft 2|2 and the cap 2|4. f.

The headstockon the shiftable'carriage |56 is indicated as a-whole -at.2|6. Thisheadstock is mounted in the upright 2| 8 on the oscillatable carriage |56. The upright 2|8 is provided with a bore in which there is positioned the4 bushing 220 and in the bushing 228 a second bushing 222 is mounted. A set screw 224 passes through the upright 2|8 and into a groove in the bushing 222 and holds it in place. A second bushing 221 is provided between parts 222 and 232. The bearing 222- is capable of a limited amount of rectilinear movement in the bushing 228 and this movement is caused by the interengagement of the cam surface 226 on the bushing 222 and the cam surface 228 on a rotatable member 238 held against the upright 2|8 by means of an end cap 232. The member 238 is rotatable loetween the cap 232 and the upright 2|8 by means of the handle 234. By turning the member 238 by means of the handle 234, the interengagement ofthe cam or threaded surfaces 226 or 228 will cause the bushing 222 to be moved either to the right-or to the left, depending upon the direction inv which the handle 234 is rotated. The purpose of this movement will be later described.

In the bushing 222 there are positioned the roller bearings 2,36. and 238 and in these bearings 236l and 238 there is mounted the shaft 248. A suitable spacing collar 242 retains the bearings 236. and 238 apart.

The shaft 248 has the enlarged head 242 which has secured thereto the hardened ring 244 and is provided with the pins 246 having the heads 248. The hardened ring 244 is used so that it may be easily replaced to accommodate for wear. The heads 248 project beyond the rim of the ring 244 and are adapted to engage in openings in the end flange of the crankshaft to hold the crankshaft and cause it to rotate with the shaft A248. The ring 244 lits against the end face of the end flange of the shaft. The pins 248 and the ring 244; are held in place by means of the ring 258 secured to the head 242 by means of the machine screws 252.

Suitable oil seals 254 and 266 are provided at both ends of the bushing 222 and are held in place by means of rings 258 and 268 respectively.

Beyond the upright 2| 8 of the oscillating frame |56 the shaft 248 is splined as indicated at 262 and this splined end 262 is received in the splined collar 264 to which the bevel gear 266 is secured. The collar 264 is rotatably mounted in suitable bearings in the gear box 268 and the gear 266 meshes with a bevel gear 218, rigidly secured to the. shaft |62. rThe gears |44 and 218 are identical as are the gears |42 and 266 so that the same rate of rotation is given to the master crankshafts 56 and 58 on the one hand, and the crankshaft 68 on the other hand.

In order to insure that there will be uniformity of rotation, the connection |38 shown in detail in Figures '7 and 8, is capable of very line adjustments to take care of lash in the gears 2, wear, etc. Ihe shaft connection |38 is formed of the two halves 212 and 214 which are secured respectively to the shafts 216 and |48. The shaft 216 is secured by a suitable adjustment connection 218 to the end of the master crankshaft 56. The two halves 212 and 214 are united by means of the bolts 288 and nuts 282. In Figure 8 it will be seen that two of the bolts 288 operate in arcuate slots 284 in the half214 ametrically opposite bolts 288 are held in place by means of set screws 233 operating in threaded openings formed in the connection half 214. By unscrewing two diametrically opposite set screws 286 and screwing inward the opposed diwhile the other di' ametrically opposite setscrews 286a veryl fine adjustment between the shafts |48 andv 216= is possible and enables the taking up of pany: inf' accuracies due to lash or wear.

Referring to Figures 2 and 10, there is illus;- trated the structure for oscillating the oscillatable carriage |56. The carriage |56 has pivoted thereto at 288 a link 298, the opposite end 282: of, which is mounted on an eccentric on the end 26g4ofa stub shaft 236. The end of the link 282 isheld between washers 288 by means of a nut, Y308 screwed onto the threaded end of the shaft. 29,6. 'Ihe shaft 286 is mounted in the bearing 3,82 positioned in an extension 384 fcrmedon the gear box 266. This gear box 268 is seouredby means of the machine screws 386 to a subframe 388 mounted on the frame 4.

This upright 383 has a bearing 3|8,v and a. dou. ble roller bearing 3|2 is positioned in a box-.3|4 secured in the end of the gear box 268, andyin these two bearings 3|8 and 3|-2 the shaftA |52` .is rotatable.

Between the box 3M and the face of the, upright 388 a gear 3|6 is secured to the shaft." |52 by means of a key 3%8. The gear 346 is heldin place by means of the collars 328 and'32f2. The gear 3|6 meshes with a second gear 32.4 keyed as at 326 to the end 328 of the stub shaft 296. The gear -324 is held to the shaft .by meanszof. the nut 338 screwed onto the threaded end of` the shaft. A roller bearing 332 is provided for the end 328 of the shaft 296 and this roller bearing is mounted in a bearing retainer 334 securedby means of the machine screws 336 to the gear to and fro movement of the link 238I will cause the carriage |56 to oscillate on the pivot pins..

|62. The reason for giving this reciprocating motion to the carriage |56 is that the width of` the emery cloth or abrasive 86 is slightly. less than the width of the bearing to be polished and in order that all of the bearing may be polished, this short reciprocating motion will move the crankshaft 68 to and fro to cause all parts thereof to come in contact with the abrasive.

In Figures 1 and 4 there are shown a plurality of spools 338 which have thereon the emery cloth 96 and these spools are mounted on suitable uprights 348 secured to the hat table 6 of the frame.

vEach polishing arm has at its end a spool 342 mounted on uprights 346 secured to the arm. These spools are mounted on suitable pivots and one edge of the spool is preferably formed with ratchet teeth 348 and a pawl 368 engages the teeth and prevents the rotation of the spool in one direction. After the crankshaft has been polished, the operator will rotate the spools 342 a suitable distance in lorder that a new surface of emery cloth will be presented for polishing the next crankshaft.

Referring to Figure 4, and particularly to the cam 38, the position of the parts is shown just before the cams 28 and 38 are to press the table 32 and its bearing heads against the bearing parts of the shaf In the position as shown, the springs |84 have begun to be compressed, and as the cams rotate further, the rollers |26 will arrive at the end of the initial or first arc A (Figure 4) of the cam. Through the entire arc A the polishing heads 82 will be held tightly against the bearings of the shaft G0, and throughout this arc the springs IM will be entirely shut. When the cams reach the end of the arc A the rollers |26 will drop into the recesses B of the cams and this drop is sufficient to enable the polishing cloth 96 to be loosened from the bearings on the shaft 60. In the operation of polishing the shafts an oil is used, and by suitably directing the oil from nozzles N (supplied from a manifold M, fed by a pipe P) onto the bearings, there -is a flushing action when this emery paper 96 is withdrawn and this flushing action will remove any free grit which may be between the bearings on the shaft 60 and the emery paper 96. After this grit has been removed, the arc C of the cam will come into play. The initial part of this arc indicated at D has the same compressive value or force against the table -32 and the rollers l26 as the value or compressive force of the part of the cam indicated by the arc A, and during the initial period of the arc C the polishing heads will be tightly compressed against the bearing parts 60. Arc C of the cam is shaped so that the pressure will gradually diminish from the initial point D to the end point E so that there will be a gradual fade-out, and when E has been reached there is substantially little or no pressure of the emery paper against the bearings. For one revolution of the cams 28 and 30 a crankshaft 60 is polished.

To remove the crankshaft and insert a second shaft, the air valve (not shown) is operated to cause the piston |96 to retract the piston |90 away from the end 206 of the crankshaft 60. This will relieve the pressure against the end of the crankshaft 60. The operator will now turn the handle 234 to cause the interengaging surfaces of the teeth 226 and 228 to withdraw the bushing Z22-and therewith the head 242--from the end of the crankshaft, or to pull the heads 248 out of the openings in the end flange of the shaft. This will enable the operator to withdraw the shaft from the oscillatable table and insert a new shaft.

We claim:

1. In a machine for polishing the bearings of acrankshaft, a carriage mounted on the machine and having a crankshaft rotatably mounted thereon, a table mounted on the machine, two master cranks mounted on the table, means to rotate the master cranks in unison, polishing arms mounted on the master cranks and adapted to polish the crankshaft bearings when in contact therewith, two rotary cams for moving the table toward the crankshaft, the shape of said cams causing the polishing arms to be tightly pressed against the bearings for an arc of about 90, the shape of said cams then allowing the tableto be withdrawn sufficiently to leave a small spacebetween the ends of the polishing armsV and the bearings to enable the polishing surfaces and the bearings to be flushed with oil, the cams then again pressing the polishing arms tightly against the crankshaft bearings, and then allowing the pressure on the arms against the bearings gradually to be lessened until the polishing arms are removed from the bearings.

2. In a machine for polishing the bearings of a crankshaft, a carriage mounted on the machine and having a crankshaft rotatably mounted thereon, a table mounted on the machine, two master cranks mounted on the table, means to rotate the master cranks in unison, polishing arms mounted on the master cranks and adapted to polish the crankshaft bearings when in contact therewith, two rotary cams for moving the table toward the crankshaft, the shape of said cams causing the polishing arms to be tightly pressed against the bearings for an arc of about the shape of said cams then allowing the carriage to be withdrawn sufficiently to leave a small space between the ends of the polishing arms and the bearings to enable the polishing surfaces and the bearings to be flushed with oil, the cams then again pressing the polishing arms tightly against the crankshaft bearings, and then allowing the pressure on the arms against the bearings gradually to be lessened until the .polishing arms are removed from the bearings, and means to reciprocate the carriage during the polishing operation.

3. In a crankshaft lapping machine, means rotatably and reciprocably to mount the crankshaft to be polished, a table movable to and from the crankshaft, two master crankshafts rotatably mounted on the table, means on the master crankshafts to cause the bearings on the rst named crankshaft to be polished when the machine is operated, cam means to move the table to and from the crankshaft, said cam means causing the polishing means to be tightly pressed against the bearings of the crankshaft for part of the movement of the cam means, the shape of the cam then allowing the table to be withdrawn from the bearings sufficiently to leave a small space between the ends of the polishing means and the crankshaft bearings, the cam means then again causing the polishing means to be tightly pressed against the bearings for a definite arc of movement of the cam means and then gradually diminishing the pressure until the polishing arms are released from the bearings, a power shaft mounted on the machine, means to drive one of the crankshafts from the power shaft, means interconnecting the two master cranks and causing the second crankshaft to be driven from the first, and means connected to the power shaft to rotate and reciprocate said first-mentioned means.

FRANK W. HAEGER. EMIL P. ROI-IRBACH. 

